10.18453/rosdok_id00005301 Zhou, Ying Ying Zhou http://d-nb.info/gnd/1395759952 Universität Rostock 2024 300 Social sciences 310 General statistics 2024 en https://purl.uni-rostock.de/rosdok/id00005301 urn:nbn:de:gbv:28-rosdok_id00005301-6 As a cumulative thesis, I investigated 3 sensitive periods of life in 3 studies. Study 1 found that cognitive function of 55-69 years old improved significantly in southern and central Europe, but not in northern Europe. Study 2 found that those who started ECEC older than 3 had higher scores of internalizing psycho-social problems; those who started ECEC younger than 1 had significantly higher scores for externalizing psycho-social problems in West Germany, but not in East Germany. Study 3 showed that LEI in people of 75+ significantly increased the risk of dementia, care need and death.